Well I am trying to figure out if I need to change this. What should the SPW be at idle?? Mine is around 1.1ms but at WOT it will not go above around 5.1ms and my duty cycle is about 70%. My duty cycle will not go any higher, my VE in those areas is 95-97. My commanded AFR in PE is 12.8 but I am running more like 14.1. The offset is about 600usec right now. But I am running 33psi through holley delphia injectors.

 

BTW this is with the EBL and TBI

 

Why would my duty cycle not go above about 55-60%?? I changed the offset to 700usec and thats all it will go. My AFR is about 14.1 at WOT but commanded is 12.8. My VE at 100 map is around 97 in most upper rpm cells. I can not get them to go anymore. Is there something else I am missing here.

Thanks.

 

The Injector Correction Offset values are to compensate for the opening time of the injector. Basically it makes up for the time that the injector is not flowing fuel. I don't know what they should be for the Delphi injectors. If the value is too low then the low MAP areas of the VE table will tend to move back upwards. Giving a bathtub shape to the VE table (or an area of it). IT the offset corrections are too high the VE table can drop off to 0.

If your VE is in the high 90's, and the duty cycle is low (55 - 60%), then the BPC value(s) need to be increased (BPC vs VAC). That will add PW.

On another note, just an FYI, if the VE is in the high 90's, and the duty cycle is in the high 80's/90's, then a larger injector or more fuel pressure is required.

RBob.

 

Ok that makes sense then. Thats what my table was doing before i increased to 600. I will try going back to 600 and then increasing my bpc. Right now it is 91, but the injectors I am running are 85pph at 21psi and I am running them at 33psi. MAybe my calculations are wrong. Or the injectors were changed in this holley unit, as it is used. I will have to pull them and look.

On a side note, the new EBL board has not given one issue, works perfect and I have put a lot of miles on it already.

 

Alright well I changed it to 100 and I am a lot better now. Running around 13.2AFR but I am maxed on the duty cycle so off to bigger injectors. Need to fit the stock GM pod on the holley base.

Now that I am running it higher in the RPM range I am way over going the 255 gms sec range. I hit it at about 4400 or 4500 rpms when redline right now is set to 5500rpms. With the EBL is there any way to get passed this or no?? I know the maf guys have gotten passed it by lossing some resolution.

BTW man does it really kick and go now with the AFR getting closer, just need a little more fuel so I can run a little more SA. Breaking 33" tires at 20-30mph roll is just easy.

 

There isn't any issues with the airflow going above 255 gms/sec. The only place that uses the airflow that high is the IAT/CTS blend table. Where it is rare to have any real amount of CTS used at those airflows. It is different for the MAF users.



RBob.